in windows xp go to text services and input language and then add the chinese language. Keyboardlayout/ime value is : "chinese (simplified) - Micrsoft pinyin ime 3.0"
Vista shouldn't be that far off i think.
Hmm, could it be that both account can run in admin mode and normal account mode? I heard something abt vista running u in normal user mode most of the time for "security reasons" and causes u not being able to stop the restart to ur computer for auto update to complete. Sorry can't help u much on this. Formatted my laptop the 3rd day after i got so pissed with vista.